(1) Field of the Invention
This invention relates to a multi-stage absorption refrigeration system suitable for use as an airconditioning system for effecting space cooling and space heating, for example.
(2) Description of the Prior Art
An absorption refrigeration system equipped with more than three generators is disclosed in U.S. Pat. No. 3,742,728 or U.S. Pat. No. 3,831,397, for example.
Multi-stage absorption refrigeration systems are characterized by having a high coefficient of performance (refrigeration effect/heat input). In a typical multi-stage absorption refrigeration system, a refrigerant in a gaseous state produced in a first generator is used as a heat source of a second generator, a refrigerant in a gaseous state produced in the second generator is used as a heat source of a third generator and in this way refrigerant gases produced in the preceding generators are successively used as heat sources of the next following generators. To this end, the temperature and pressure of the refrigerant in the gaseous state in the first generator should be so high that gas refrigerant can be produced even in the final generator. Such high temperature level as serves this purpose would accelerate the process of corrosion of walls of the first generator. The inventions disclosed in the documents referred to hereinabove provide no solution for essentially preventing such corrosion.
In U.S. Pat. No. 3,367,134 and U.S. Pat. No. 3,367,135, there is a description to the effect that the cooling medium coming from the condenser section flows through tubes in the absorber, section before being discharged. However, there is found no description in the documents referred to hereinabove with respect to the object for flowing the cooling medium in the manner described, nor to the combination of the aforesaid flow system of the cooling medium with the multi-stage absorption refrigeration cycle. Further, there is disclosed no absorbent solution supply system which supplies an absorbent solution directly to all generators without passing through other generators than the generator to which it is destined.